Detect If A Web User Is Currently Logged In Google?

Suppose I want to display certain content only if I know the user coming to my website has a valid Google Account and it's logged into that account. Is there any way to do this in

Solution 1:

This blog claims to have done it, via checking for image return values linked to the social platforms provided by G+ / twitter / etc

http://www.tomanthony.co.uk/blog/detect-visitor-social-networks/

<img style="display:none;"
onload="show_login_status('Google', true)"
onerror="show_login_status('Google', false)"
src="https://accounts.google.com/CheckCookie?continue=https%3A%2F%2Fwww.google.com%2Fintl%2Fen%2Fimages%2Flogos%2Faccounts_logo.png&followup=https%3A%2F%2Fwww.google.com%2Fintl%2Fen%2Fimages%2Flogos%2Faccounts_logo.png&chtml=LoginDoneHtml&checkedDomains=youtube&checkConnection=youtube%3A291%3A1"
/>

Solution 2:

<scripttype="text/javascript">functionshow_login_status(network, status){

    if(status == false){
        alert('NOT LOGGED IN');
    }
    if(status == true){
        alert('Logged In');
    }


}


</script><imgstyle="display:none;"onload="show_login_status('Google', true)"onerror="show_login_status('Google', false)"src="https://accounts.google.com/CheckCookie?continue=https%3A%2F%2Fwww.google.com%2Fintl%2Fen%2Fimages%2Flogos%2Faccounts_logo.png&followup=https%3A%2F%2Fwww.google.com%2Fintl%2Fen%2Fimages%2Flogos%2Faccounts_logo.png&chtml=LoginDoneHtml&checkedDomains=youtube&checkConnection=youtube%3A291%3A1"
/>

This will work.